Carabiners, snap-hooks, and releasable clamps are used in a variety of applications for releasably coupling objects to one another. For example, a rock climber may use one or more carabiners to releasably secure a rope to a protection device during vertical ascension. Carabiners generally include a frame, a gate, and a releasable gate closure mechanism. The gate is configured to releasably engage the frame so as to form a continuous inner region which can mechanically couple to one or more objects. The releasable gate closure mechanism is configured to allow the gate to be selectively pivoted with respect to the frame to facilitate addition or removal of items from the continuous inner region. The releasable gate closure mechanism simultaneously biases the gate toward a closed configuration with respect to the frame so as to maintain mechanical coupling of items within the continuous inner region. A wide variety of frame, gate, and biasing systems exist to specifically accommodate particular applications and/or manufacturing costs for the carabiner.
Wire-gate type carabiners represent a particular gate construction, biasing system, and gate-frame interface. Wire-gate carabiners utilize a substantially elongated, looped rigid wire member for the gate portion of the carabiner system. In general, the lengthwise ends of the wire member gate are oppositely coupled to the frame such that the spring/rebound rigidity of the gate creates the automatic biasing mechanism. As the gate is selectively pivoted about the frame coupling point, the torsional properties of the wire automatically generate a biasing force that mechanically urges the gate back toward the closed configuration. The frame includes a gate interface region which generally includes a hook over which the loop of the gate is configured to extend while in the closed configuration. The reliable positioning of the loop with respect to the hook significantly affects the structural ability of the carabiner to counteract shear forces. Due to the inherent minimal gate thickness, wire-gate type carabiners are usually lighter in overall weight than other corresponding carabiners. However, the unique requirements and limitations of the gate/frame interface have resulted in an inability to manufacture wire-gate type carabiners for certain applications.
A variety of specialized carabiner designs are configured to include specific mechanical characteristics that optimize particular functionalities. One type of specialized carabiner includes a hookless or keyed engagement coupling scheme between the gate and frame when in the closed configuration. This type of gate/frame engagement scheme optimizes the engagement and disengagement of the carabiner with particular items such as a bolt hanger or a non-sling protection device. However, structural modifications must be incorporated to the gate/frame interface to maintain the necessary reliable coupling between the gate and frame in the closed configuration. For example, some form of three-dimensional keyed interface must generally be incorporated to provide the necessary engagement between the gate and frame. The three dimensional keyed interface increases the reliability of the coupling between the gate and frame without the introduction of a hook structure. Various problems exist with conventional hookless carabiners, including manufacturing cost, susceptibility to debris-related obstruction, durability, and weight.
Therefore, there is a need in the industry for a carabiner that overcomes the limitations of existing systems in a cost efficient manner.